Avantes offers this specially designed series of reflection probes to effectively measure reflection in powders and thick fluids. The probes allow the user to simply dip the probe into the powder or thick fluids to conduct the measurements.
The illumination leg of the probe is connected to a light source and carries light to the sample via a bundle of six fibers. At the probe tip, a 45-degree fused silica window illuminates the sample and collects the indirect reflections, which are carried by a single fiber to the spectrometer. The 45-degree angle of the probe prevents the measurements of direct back reflection from the window, thus improving the dynamic range of your measurement.